Chromium Nicotinate Supplementation: Effects on Body Composition and Strength in Female Colleigate Athletes Participating in Off-Season Training

Abstract

LEARNING OUTCOME: To evaluate differences in body composition, upper and lower body strength, and macronutrient intake in female collegiate athletes consuming a supplement of Cr Nic or a placebo This study investigated the relationship between chromium nicotinate (Cr Nic) supplementation and strength, body composition, and macronutrient intake in female collegiate athletes participating in off-season strength training. Seventeen collegiate athletes were randomly assigned in a double-blind fashion to receive daily either a placebo (Pl; n=10), or 200 micrograms Cr Nic (Cr; n=7) over eight weeks of a progressive strength training program. The athletes were pair-matched using body composition as the primary variable of interest, and strength as a secondary variable when applicable. Subjects were tested at baseline and at week eight for body composition, using skinfold measurements; and for strength, using a 1-repetition maximum technique for both upper and lower body strength. The athletes trained all major muscle groups 3 times a week. They were encouraged to maintain their usual diets over the course of the experiment. Diets were not significantly different with the Cr group consuming an eight week average of 1957 kcals (14% protein, 60% carbohydrate, 25% fat, & 2% alcohol), and the Pl group consuming 1748 kcals (14% protein, 60% carbohydrate, 26% fat, & 1% alcohol). Although there were no statistically significant differences in strength, upper body strength increased by 5 pounds (5.49%) in the Cr group, and 9 pounds (9.64%) in the Pl group. Lower body strength increased by 9 pounds (3.05%) in the Cr group, and 13 pounds (5.34%) in the Pl group. Since no treatment effect occurred, the gain in strength was attributed to the strength training program the athletes completed. Although the difference was not statistically significant, body fat increased by .60% in the Cr group, and by .10% in the Pl group. In conclusion, 8 weeks of Cr Nic supplementation, in conjunction with a progressive strength training program did not appear to increase strength or decrease body fat in these female athletes. Encouraging clients to use strength training would be an effective technique to increase muscle mass, while Cr Nic supplementation appears, in this population, to be of little benefit